Polyparasitism with Schistosoma haematobium and soil‐transmitted helminth infections among school children in Loum, Cameroon

Abstract

SummaryPrevalence and abundance of Schistosoma haematobium and soil-transmitted helminths (STH) were assessed among a total of 1600 pupils (urine, n ¼ 1190; faecal samples, n ¼ 1454) attending five schools in Loum, Littoral Province, Cameroon, with the specific aim of assessing the extent of polyparasitism and the extent to which infections were focused in particular subsets of the study group. Prevalence of S. haematobium was 62.8% with an abundance (arithmetic mean of egg counts) of 54 eggs/10 ml urine. For the STH these were 47.7% and 619 eggs per gram of faeces (EPG) for Trichuris trichiura, 65.5% and 3636 EPG for Ascaris lumbricoides, and 1.4% and <0.1 EPG for hookworms. Most children (90.3%) were infected with at least one of these four species, the largest proportion (34.3%) carrying two species; 27.4% carried three and 1.1% carried concurrently all four species of parasites. The average number of species harboured increased with age, as did the prevalences of S. haematobium and T. trichiura but not that of A. lumbricoides. All STH showed marked differences in prevalence between the five schools but only T. trichiura varied significantly between sexes. Mean abundance of infection varied significantly between age classes, among schools and between the sexes, with females showing heavier mean EPGs for A. lumbricoides and T. trichiura and males higher mean eggs/10 ml urine for S. haematobium infections. A highly significant association was detected between A. lumbricoides and T. trichiura, that was not context-dependent. This was confirmed in quantitative analyses after controlling for differences in abundance between schools, sexes and age classes. A weaker contextdependent association (prevalence data) was detected between S. haematobium and A. lumbricoides (sex-and age-dependent) but quantitative associations between these two species, as well as between S. haematobium and T. trichiura, were not convincing.

Diversity of human intestinal helminthiasis in Lao PDR

“…Our data underscore that multiparasitism is very common in Lao PDR and these findings support observations from neighbouring countries such as Vietnam [25][26][27] and from other parts of the developing world. 21,22,[28][29][30] Hence, our results and those from other groups who worked in Lao PDR 7,8 call for concerted action to remedy the issue of multiparasitism. Of particular public health relevance are our results in relation to the diversity of trematodes identified.…”

Helminth infections: the great neglected tropical diseases

“…Finally, an increasing number of studies of helminth epidemiology have shown that it is common for individuals to be infected with more than one species of helminth (21,(58)(59)(60)(61)(62)(63). There is also evidence suggesting synergism and antagonism in concurrent intestinal nematode and schistosome infections (62-64) as well as filarial nematode infection and soil-transmitted helminth infections (65).…”

“…There is also evidence suggesting synergism and antagonism in concurrent intestinal nematode and schistosome infections (62-64) as well as filarial nematode infection and soil-transmitted helminth infections (65). A number of epidemiological studies have indicated that individuals infected with multiple species of helminth often harbor heavier infections than individuals infected with a single helminth species (58)(59)(60)(61). An important consequence of simultaneous infection with the parasites that cause hookworm, schistosomiasis, and malaria is severe anemia (21,66).…”

The impact of health education on the prevalence of faecal-orally transmitted parasitic infections among school children in a rural community in Cameroon

“…In Cameroon, IPIs are recognized by the Ministry of Public Health to be an important public health problem ranking second to malaria [7]. There has been periodic de-worming in most endemic areas in the country, but studies suggest that there is a high rate of re-infection [8].…”